//https://www.luogu.com.cn/problem/P2573

#include<iostream>

using namespace std;
const int N = 1e5 + 10, M = 1e6 + 10;
typedef pair<int, int> node;
node a[M];

int cnt;

void dfs(int x)
{

}

int main()
{

	return 0;
}